Uroporphyrinogen III synthase () is an
enzyme involved in the
metabolism of the cyclic
tetrapyrrole compound
porphyrin. It is involved in the conversion of
hydroxymethyl bilane
Hydroxymethylbilane, also known as preuroporphyrinogen, is an organic compound that occurs in living organisms during the synthesis of porphyrins, a group of critical substances that include haemoglobin, myoglobin, and chlorophyll. The name is oft ...
into
uroporphyrinogen III. This enzyme
catalyses the inversion of the final
pyrrole
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4 H4 NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-meth ...
unit (ring D) of the linear tetrapyrrole molecule, linking it to the first pyrrole unit (ring A), thereby generating a large macrocyclic structure, uroporphyrinogen III.
The enzyme
fold
Fold, folding or foldable may refer to:
Arts, entertainment, and media
* ''Fold'' (album), the debut release by Australian rock band Epicure
*Fold (poker), in the game of poker, to discard one's hand and forfeit interest in the current pot
*Above ...
s into two alpha/beta
domains connected by a beta-ladder, the
active site
In biology and biochemistry, the active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of amino acid residues that form temporary bonds with the substrate (binding site) a ...
being located between the two
domains.
Pathology
A deficiency is associated with
Gunther's disease
Gunther disease is a congenital form of erythropoietic porphyria. The word porphyria originated from the Greek word porphura. Porphura actually means "purple pigment", which, in suggestion, the color that the body fluid changes when a person has Gu ...
, also known as congenital erythropoietic porphyria (CEP). This is an
autosomal recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
inborn error of metabolism that results from the markedly deficient activity of uroporphyrinogen III synthase.
References
External links
*
EC 4.2.1
{{lyase-stub